I'm pretty sure Lovely Rita was done with a CW HeNe. I know Eidetic has some info in his collection about the artist...
I seem to remember that the disc is split up into over 1000 "slices", where each one is an exposure of the model as she was rotated on a platform. As the model turned, so did the disc, so each exposure captures a slightly different view.
Holography is all about long coherence length, but there are several different lasers that fit the bill.
Adam